The iPhone 4S had a tough hurdle to overcome after the death of Steve Jobs and the negative reaction to the 3GS as a sequel to the iPhone 3. The phone was almost identical to its predecessor but offered improvements in speed, cell reception and storage. The most notable addition was the introduction of Siri, the phone's voice-activated digital assistant. Major criticisms of the phone included limited battery life, Siri limitations and the fact that it wasn't an iPhone 5.